Skin Allergy Overview
Skin irritations are caused by a variety of factors. These include heat, immune system disorders, medications and infections. When an allergen is responsible for triggering an immune system response, the irritation is an allergic skin condition.
Allergic contact dermatitis occurs when your skin comes in direct contact with an allergen. For instance, if you have a nickel allergy and your skin comes in contact with jewelry made with even a very small amount of nickel, you may develop red, bumpy, scaly, itchy or swollen skin at the point of contact.
Atopic dermatitis (eczema) is a chronic skin condition related to immune disfunction in the layers of the skin. It usually begins in infancy or early childhood. It is often associated with asthma, allergic rhinitis (hay fever) or food allergy. This progressive sequence is called the atopic march.
Urticaria (hives) are an inflammation of the skin triggered when the immune system releases histamine, causing small blood vessels to leak leading to swelling in the skin. Swelling in deep layers of the skin is called angioedema.
Hives can result from non-allergic causes such as heat or exercise. Hives can also be an allergic reaction to medications, foods or insect bites.
Although often uncomfortable and sometimes painful, hives and eczema are not contagious.
Skin conditions are one of the most common forms of allergy treated and managed by an allergist / immunologist, a physician with specialized training and expertise to accurately diagnose your condition and provide relief for your symptoms.
Skin Allergy Symptoms & Diagnosis
Redness, swelling and itching are common to most skin allergies. Yet there are some differences that help in the diagnosis of specific conditions.
Urticaria (Hives) Symptoms
Swelling or raised red or white bumps or welts that :
- Can cover large areas and migrate from one spot to another
- Range in size
- Appear anywhere on the body
Angioedema often appears on the face around the eyes, cheeks or lips. This deeper layer of swelling can also occur on hands or feet, genitals, or inside the bowels or throat.
In acute hives, the welts disappear within minutes to a few weeks. Chronic hives last for months or even years.
Atopic Dermatitis (Eczema) Symptoms
Itchy bumps, blisters or very dry skin that :
Appear as red to brownish-gray colored patches
May “weep” or leak fluid that crusts over when scratched
In infants, eczema often appears on the cheeks, forehead or scalp. Children are prone to have the rash at the bend of the elbow joint, wrists, behind the knees and behind the ears. Adolescents and young adults typically have the rash in the same locations as children, as well as on the hands and feet.
People with atopic dermatitis can also have an extra crease, called a Dennie’s line, across the lower eyelids.
Identifying the cause of the skin irritation is essential to relieving the symptoms. An allergist / immunologist will take a complete health history and may perform tests to diagnose allergies that could be causing symptoms.